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Updated: Jun 13, 2026

Methods for Facilitating Microbial Growth on Pulp Mill Waste Streams and Characterization of the Biodegradation Potential of Cultured Microbes
Published on: December 12, 2013
Treatment of paper and pulp mill effluent by coagulation
Parmesh Kumar Chaudhari1, Bidyut Majumdar, Rumi Choudhary
1Chemical Engineering Department, National Institute of Technology, Raipur, India. pkchaudhari@rediffmail.com
Abstract:
Pulp and paper mill effluent is highly polluting and is a subject of great environmental concern. In the present research we studied the removal of chemical oxygen demand (COD) and colour from paper mill effluent, using the coagulation process. A batch coagulation study was conducted using various coagulants such as aluminium chloride (AlCl3), polyaluminium chloride (PAC) and copper sulphate (CuSO4 x 5H20). The initial pH of the effluent had a tremendous effect on the COD and colour removal. The PAC reduced COD by 83% and reduced colour by 92% at an optimum pH of 5.0 and a coagulant dose of 8 mL L(-1). With AlCl3, at an optimum pH of 4.0 and a coagulant dose of 5 g L(-1), 72% COD removal and 84% colour removal were observed. At an optimum pH of 6.0 and a mass loading of 5 g L(-1), 76% COD reduction and 78% colour reduction were obtained with copper sulphate. It was also observed that, after addition of coagulant, the pH of the effluent decreased. The decrease in the pH was highest with AlCl3, followed by PAC and then CuSO4 x 5H20.
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